Consumers’ behaviour can be studied outside the retail shops also in order to assess a packaging design in relation to marketing and product presentation. Such methods give you more time to evaluate in details. But by nature the test person always have a distance to the realistic shopping process and as a result of this answers can be systematically wrong. On this site you only find instruction to perform focus groups.
See also under Packaging Science - Marketing - Evaluating Tests
Focus groups are qualitative tests excellent for obtaining detailed information on the functionality of the packaging design. But the weak side is that in practice you will only have resources for testing small groups of test persons. It can be critical that the tests are not statistical safe and many companies use both evaluation tests parallel to hall test and/or observing tests.
Programmed interviews are another evaluation test technology but it is not described on this website. Both techniques take time and test persons have to be present in 1-4 hours. It will be difficult to test under realistic conditions. You have to make an appointment beforehand with your test persons and also the test person will only evaluate own behaviour. The strong side of this evaluating test is the time used for focusing on the specific problem. Often ideas and problems unknown for the designer are located. And alone for this reasons it is an excellent tool for a packaging designer.
You will find instructions on page: